Pest identification
What's eating my st. john's wort?
Aphids
Signs: Distorted, sticky shoot tips; visible colonies of small green or black insects; sooty mould on honeydew deposits below.
Control: Spray with insecticidal soap or neem oil; encourage natural predators; physically remove by hand or strong water spray.
St. John's Wort beetle (Chrysolina hyperici / C. quadrigemina)
Signs: Adults and larvae eat foliage down to bare stems; characteristic round holes, then complete defoliation in severe infestations (mainly western US, Australia).
Control: This is a biocontrol agent for invasive Hypericum — consult local extension advice before controlling; handpick where the plant is cultivated.
Rabbits
Signs: Clean cuts on young stems close to the ground; emerging shoots browsed off in spring and early summer.
Control: Place wire-mesh guards (at least 60 cm tall) around new plantings; apply rabbit-repellent sprays on stems.
Keep st. john's wort pest-free
Healthy plants resist pests best. Get the basics right:
St. John's Wort pests — FAQ
What is eating my st. john's wort?
St. John's Wort (Hypericum perforatum) is deer-resistant and relatively tough, but aphids can build up on tender stems and St. John's Wort beetle (Chrysolina hyperici, a biological control agent in North America) can defoliate plants. Rabbits nibble young growth, and slugs damage seedlings. Aphids are the most common garden complaint.
How do I get rid of aphids on st. john's wort?
Distorted, sticky shoot tips; visible colonies of small green or black insects; sooty mould on honeydew deposits below. Spray with insecticidal soap or neem oil; encourage natural predators; physically remove by hand or strong water spray.
How do I get rid of st. john's wort beetle (chrysolina hyperici / c. quadrigemina) on st. john's wort?
Adults and larvae eat foliage down to bare stems; characteristic round holes, then complete defoliation in severe infestations (mainly western US, Australia). This is a biocontrol agent for invasive Hypericum — consult local extension advice before controlling; handpick where the plant is cultivated.
How do I get rid of rabbits on st. john's wort?
Clean cuts on young stems close to the ground; emerging shoots browsed off in spring and early summer. Place wire-mesh guards (at least 60 cm tall) around new plantings; apply rabbit-repellent sprays on stems.